Direct lighting systems, although most commonly used, possess certain disadvantages in the form of glare and veiling reflections. The lighting industry has developed indirect luminaires which reflect light from a source onto interior surfaces such as walls and ceilings. For example, a product sold under the name Super Tube by Columbia Lighting of Spokane Wash. includes a rotatable reflector that partially surrounds a fluorescent lamp within the luminaire. Although this type of indirect luminaire is highly desirable, there is a tendency to illuminate the ceiling or wall nearest the luminaire to a noticeably greater extent than portions of the wall or ceiling lying a distance from the luminaire. These areas are termed "hot spots". In an attempt to eliminate "hot spots" a second reflector has been placed between the fluorescent lamps and the wall or ceiling. However such a design has not solved the uneven light distribution problem.
U.S. Pat. No. 4,390,930 and Design Pat. No. Des. 274,657 propose an indirect lighting fixture which includes a lens as a extension of the underlying reflector to reduce glare and increase the light distribution. Unfortunately, the use of a lens increases manufacturing costs and necessitates expenditure of labor since the lens requires constant cleaning. In addition, the partial enclosure of the fluorescent lamps inhibits the escape of heat from the lamps and, thus, decreases the operating efficiency of the fluorescent lamps within the luminaire.
An indirect luminaire which solves these problems encountered by the prior art devices would be a great advance in the lighting industry.